1. Magnetic upper and lower shells. Hidden cartridge. 2 Inhale and button-activated options for easy operation. 3. Three (3) voltages to meet different needs. 3.4V, 3.7V, 4.0V. 4. Capacity of battery: 650MAH. 5. Charging current: 500MA. 6. Charging input voltage: USB 5V. 7. Supporting load: 0.8 Ω to 10 Ω.